KR102173184B1 - Apparatus and method for blood flow change measurement using adsorption cup - Google Patents

Abstract

The present invention relates to a blood flow change measuring apparatus and a measuring method for measuring a change in blood flow through a change in pressure of air inside a vacuumed suction cup using a pressure change measuring sensor located inside the suction cup.
The apparatus for measuring blood flow change of the present invention comprises: an adsorption cup having a hole in the upper portion and made to be attached to the skin; An air pressure change measuring sensor mounted inside the suction cup and detecting a change in air pressure inside the suction cup as a blood flow conversion signal; It characterized in that it comprises a blood flow change measurement sensor having; a packing part, which prevents air from leaking from the through hole when the wire connected to the barometric pressure change measurement sensor is inserted into the through hole.

Description

Apparatus and method for blood flow change measurement using adsorption cup}

The present invention relates to a blood flow change measuring apparatus and a measuring method for measuring a change in blood flow through a change in pressure of air inside a vacuumed suction cup using a pressure change measuring sensor located inside the suction cup.

Pulse wave refers to the wave of blood that forms waves in the heart and propagates, and although slightly different depending on arteries and veins, the characteristics of pulse and pulse waves generally depend on the pain of the heart, the characteristics of the blood vessel wall, and the pressure within the blood vessel. In particular, the pulse wave transmission rate (PWV: PulseWaveVelocity) has a slight difference between the arteries close to the heart and the arteries far away.

In general, methods commonly used for measuring changes in blood flow include a photovoltaic pulse wave sensor that measures at the peripheral part of a tissue, a method that uses pressure changes for measurement in major arterial blood, and a method that uses Doppler ultrasound. When examining major arterial diseases, blood flow changes in major arterial blood such as carotid artery, radial artery, femoral artery, etc., which are major arterial blood, are not measured at the periphery. Measure the change in pressure due to change.

Conventional blood flow change measuring devices in major arterial blood have been developed in the form of straps or forceps to fix the pressure sensor on the measurement site, and require more than a certain force (pressure) to detect pressure changes caused by blood flow changes in arterial blood. . At this time, since it must be fixed to the subject's measurement area with a certain force (pressure), a feeling of restraint and a sense of resistance such as tightening of the measurement area will be felt, and if a strong force (pressure) is applied, it may affect the change in blood flow of the subject and damage the measurement data. have.

When using a strap as shown in FIG. 1, the subject's neck is tightened when measuring blood flow changes in the carotid artery, which causes a problem of lowering the breathing activity. When measuring the femoral artery, it is necessary to strongly compress the femur to fix the strap. I can feel it. The blood flow change measuring device in the form of a forceps may also give a feeling of rejection to the subject because it must strongly press the measurement site. In addition, in the case of a blood flow change measurement device using a strap for fixing, the strap is pulled and fixed at a certain strength. If the strap is stretched or loosened by the tension acting on the strap during measurement, the measured data is affected by the change in blood flow and must be measured again. Also, the blood flow change measuring device in the form of a forceps must be measured again when the part in contact with the sensor is distorted due to the movement of the subject when measuring the blood flow change.

In order to solve the above problems, recently, when measuring the femoral artery, a method has been developed in which the measurer directly contacts the sensor on the femoral part of the subject, but this has the inconvenience that the measurer must keep pressing the same area with a constant pressure. .

Therefore, in order to facilitate the measurement of blood flow changes in the carotid artery, the radial artery, and the femoral artery, which mainly measure blood flow changes, the present invention attaches an adsorption cup to the corresponding site and adsorbs We propose a blood flow change measurement device and a measurement method using an adsorption cup and an atmospheric pressure change measurement sensor that detects the change in blood flow by detecting the change in pressure of the air in the suction cup due to the change in blood flow in the blood vessel through the barometric pressure change measurement sensor located in the cup. .

As a prior art, there is Korean Patent No. 10-1814817'Smart Cupping Treatment Device'. The present invention is to monitor the blood flow rate at the treatment site in real time during cupping treatment to appropriately adjust the intensity of negative pressure or thermal stimulation according to the blood flow state.The elastic membrane is positioned between the cupping device and the skin, and the blood flow rate is measured at the center of the bottom of the elastic membrane. A sensor is mounted to measure blood flow, but the blood flow measurement sensor is measured using a laser Doppler or ultrasonic Doppler effect. In this case, since the elastic membrane increases according to the pressure in the cupping machine, it may affect the measurement data, and thus there may be some problems in the accuracy and precision of blood flow measurement.

The technical problem to be solved by the present invention is to provide a blood flow change measuring device that measures changes in blood flow through a change in air pressure inside a vacuumed suction cup using a pressure change measuring sensor located inside the suction cup.

Another technical problem to be solved by the present invention is adsorption to the corresponding site to facilitate measurement of blood flow changes in the carotid artery, radial artery, and femoral artery, which mainly measure blood flow changes. A blood flow change measurement device using a suction cup and an atmospheric pressure change measurement sensor, which measures the change in blood flow by detecting the change in pressure of the air in the suction cup by the change in blood flow in the blood vessel through the air pressure change measurement sensor located in the suction cup after attaching the cup. It is to provide a method of measurement.

In order to solve the above problem, the apparatus for measuring blood flow change of the present invention comprises: an adsorption cup having a hole in the upper portion and made to be attached to the skin; An air pressure change measurement sensor mounted on the inside of the suction cup and detecting a change in the air pressure inside the suction cup as a pulse wave; When the wire connected to the barometric pressure change measurement sensor is inserted into the through hole, a stopper that blocks between the wire and the suction cup in the through hole; It characterized in that it comprises a blood flow change measurement sensor having a.

In addition, the blood flow change measuring apparatus of the present invention, by using a pressure change measuring sensor located inside the suction cup, detecting as a pulse wave signal through the pressure change of the air inside the suction cup, blood flow change measuring sensor; A signal preprocessing unit amplifying the pulse wave signal detected by the blood flow change measurement sensor, removing noise, and converting it into a digital signal; It characterized in that it comprises a; processing unit for transmitting the pulse wave signal input from the signal preprocessing unit to the computer through the transmission and reception unit.

There are three sensors for measuring blood flow changes to be installed in the carotid artery, the radial artery, and the femoral artery.

The apparatus for measuring blood flow change of the present invention measures changes in blood flow through a change in air pressure inside the vacuumed suction cup by using an air pressure change measuring sensor located inside the suction cup. In other words, in order to facilitate the measurement of blood flow changes in the carotid artery, radial artery, and femoral artery, which mainly measure blood flow changes, a suction cup is attached to the relevant site and the pressure located within the suction cup. The change in blood flow is measured by detecting the change in the pressure of the air in the suction cup due to the change in blood flow in the blood vessel through the change measurement sensor. Therefore, it is easy to use, the measuring device is simple, the restraint to the subject is less, and the probability of a measurement error due to the subject's movement during measurement is relatively small.

Therefore, the present invention can provide the following effects.

First, the present invention, in measuring the blood flow change of the existing major aneurysm, when using the existing strap or forceps form, a feeling of restraint caused by fixing to the measurement site of the subject with a certain force (pressure), etc. An ergonomic design that can minimize the sense of rejection, and after attaching the adsorption pad to the skin regardless of the area where the major aneurysm is measured, the adsorption pad is contracted or air is removed from the outside and adsorbed to fix it. It provides a function to measure the change in blood flow of the subject with a simple design.

Second, when the measurer attaches the blood flow change measurement device of the subject, the conventional method involves the hassle of adjusting the length of the strap and adjusting the size of the tongs according to the measurement part, and the risk of having to re-measure because the strap is stretched or the clamping position is changed. However, the ergonomic design using an adsorption pad provides convenience to measure changes in blood flow in blood vessels by attaching it to the subject's skin in a one-touch format regardless of the measurement area.

Third, the blood flow change measuring device in blood vessels using the form of a conventional strap and forceps requires force (pressure) to fix the sensor part at the measuring position and measure the blood flow change. Contamination may cause a risk of misdiagnosis or misdiagnosis, but the blood flow change measurement device in blood vessels using an adsorption pad does not require an additional fixing device, and the pressure change caused by blood flow changes in the blood vessels is transmitted to the skin in an environment attached to the skin. By utilizing the principle that the generated vibration is detected by the air pressure change measurement sensor through the air between the adsorption pad and the skin, it is possible to measure the change in blood flow in the blood vessel without external force (pressure), thus providing the effect of minimizing measurement data errors.

1 is an example of a state diagram of use of a blood flow change measuring device using a conventional commercially available strap.
2 is a perspective view of a blood flow change measurement sensor using a suction cup according to an embodiment of the present invention.
3 is a cross-sectional view of the absorption cup-type blood flow change measurement sensor of FIG. 2.
4 is another example of an apparatus for measuring changes in blood flow.
5 is an example of a state diagram of use of the suction cup-type blood flow change measurement sensor of FIG. 4.
6 is an example of an air pressure change measurement sensor capable of measuring temperature applied in the present invention.
7 is a block diagram illustrating a configuration of a blood flow change measuring apparatus according to the present invention.
8 shows blood flow change measurement sensors 100 applied to FIG. 7.
9 is an example of a result of measuring a femoral artery with a blood flow change measurement sensor of the present invention and a sensor using a commercially available strap.
10 is a flowchart illustrating a process of transmitting a blood flow change signal from the signal measurement unit 70 of FIG. 7 to the analysis unit 200.
11 is a flowchart illustrating a process of detecting a PWTT by detecting a peak in each blood flow change signal in the operation processing unit 220 of the analysis unit 200 of FIG. 7.

Hereinafter, an apparatus and a measuring method for measuring blood flow changes using an adsorption cup of the present invention will be described in detail with reference to the accompanying drawings.

2 is a perspective view of a blood flow change measurement sensor using an adsorption cup according to an embodiment of the present invention, FIG. 3 is a cross-sectional view of the suction cup-type blood flow change measurement sensor of FIG. 2, and FIG. 4 is another example of the blood flow change measurement sensor. , FIG. 5 is an example of a state diagram of use of the absorption cup-type blood flow change measurement sensor of FIG. 4.

The blood flow change measurement sensor 100 is equipped with a barometric pressure change measurement sensor 170 at the center of the inner side of the suction cup 105 in the form of a buhwang cup. The upper central portion of the suction cup 105 is provided with a through hole 120 for inserting a wire (i.e., a signal line, a power line, a ground line, etc.) 150 connected to the barometric pressure change measurement sensor 170, and in the through hole 120 After the wire 150 is inserted, a packing portion 110 is provided to prevent air from leaking between the wire 150 and the suction cup 105.

In order to prevent a gap from being created by a wire or the like inserted into the through hole 120 in the upper central part of the suction cup 105, FIGS. 2 and 3 are a ring in the through hole 120 in the upper central part of the suction cup 105 This is the case in which a type of packing unit 110 is installed. In this case, a ring-shaped packing part 110 is inserted between the wire 150 and the suction cup 105.

4 and 5, the packing part 110 is extended along the through hole 120 of the upper central part of the suction cup 105. In addition, a ring-shaped groove is provided on the upper portion of the suction cup 105 of FIGS. 4 and 5, and the packing part 110 is a donut-shaped packing part upper body 112 and a cylindrical packing part lower body ( 115), when the suction cup 105 is mounted, it is easy to hold by hand and has a shape (structure) to prevent slipping.

The rim 130 at the bottom of the suction cup 105 forms a step so that the thickness of the rim 130 is larger than the thickness of the other portion of the suction cup 105, and after the suction cup 105 is in close contact with the skin , Air is not leaked.

The suction cup 105 may be made of silicone, rubber, plastic, synthetic resin, or the like.

The blood flow change measurement sensor 100 may further include a temperature sensor (not shown) that measures body temperature in addition to the barometric pressure change measurement sensor 170. In some cases, as a single sensor, a sensor that measures not only changes in air pressure but also temperature can be used.

6 is an example of an air pressure change measurement sensor capable of measuring temperature applied in the present invention.

MS5803-01BA can be used as a sensor that measures not only changes in atmospheric pressure but also temperature. The barometric pressure change measurement sensor 170 outputs a change in pressure of the air in the suction cup 105 as an electrical signal.

In the case of the barometric pressure change measurement sensor 170 of FIG. 6, the sensor unit 171 is surrounded by a metal frame 172, so that it can be used directly without a separate structure, and it is possible to measure barometric pressure and temperature, so that the barometric pressure signal according to the temperature The correction of is also possible.

FIG. 7 is a block diagram illustrating the configuration of a blood flow change measuring apparatus of the present invention, and FIG. 8 shows blood flow change measuring sensors 100 applied to FIG. 7.

The blood flow change measurement device 7 includes a signal measurement unit 70 and an analysis unit 200, wherein the analysis unit 200 may be one or more of a computer, a microprocessor, or a smartphone.

The signal measurement unit 70 includes a blood flow change measurement sensor 100, a signal preprocessor 71, a control unit 75, and a transmission/reception unit 77.

The blood flow change measurement sensor 100 detects a change in air pressure from the barometric pressure change measurement sensor 170 as a blood flow change, that is, a pulse wave, and outputs an electrical signal.In the present invention, it is mounted on the carotid artery, the radial artery, and the femoral artery. In order to achieve this, three blood flow change measurement sensors 100 are provided to detect a carotid artery pulse wave signal, a radial artery pulse wave signal, and a femoral artery pulse wave signal.

The signal preprocessor 71 amplifies the carotid artery pulse wave signal, the radial artery pulse wave signal, and the femoral artery pulse wave signal detected by the blood flow change measurement sensor 100, removes noise, and converts it into a digital signal, and transmits it to the control unit 75.

The control unit 75 converts the received carotid artery pulse wave signal, radial artery pulse wave signal, and femoral artery pulse wave signal into a signal for transmission to the external computer 200, and the external analysis unit 200 through the transmission/reception unit 77 Transfer to. In some cases, the transmission/reception unit 77 may be replaced with a transmission unit. Also, the control unit 75 may be a microprocessor, a microcontroller, or the like. In some cases, the controller 75 may include a buffer or a temporary storage unit to store data of a carotid artery pulse wave signal, a radial artery pulse wave signal, and a femoral artery pulse wave at predetermined time intervals.

In the analysis unit 200, the carotid artery pulse wave signal, the radial artery pulse wave signal, and the femoral artery pulse wave signal transmitted from the signal measurement unit 70 are transmitted to the operation processing unit 220 through the transmission/reception unit 210, and the operation processing unit 220 ) Can perform cerebrovascular and cardiovascular-related analysis using the received pulse wave signal.

The operation processing unit 220 peaks from each of the carotid artery pulse wave signal, radial artery pulse wave signal, and femoral artery pulse wave signal to an inflection point having a value equal to or higher than the preset respective thresholds, that is, the carotid artery threshold, the radial artery threshold, and the femoral artery threshold. Is detected. That is, the peak is obtained through a change in slope and a variable threshold. Here, for the carotid artery threshold, the radial artery threshold, and the femoral artery threshold, a variable threshold value using an adaptive threshold algorithm may be applied. In addition, the peak here is the R point of the pulse wave and can be referred to as a peak for each period.

The operation processing unit 220 is the time difference between the carotid and radial artery pulse wave transmission rate (cr-PWTT) between the carotid and radial artery, from the time point (time) of the i-th peak of the carotid artery pulse wave, the time point of the i-th peak of the radial artery pulse wave It is obtained by subtracting (time). In addition, the operation processing unit 220, the pulse wave transmission rate (cf-PWTT) between the carotid and femoral arteries is the time difference between the carotid artery and the femoral artery, from the time point (time) of the i-th peak of the carotid artery pulse wave, the i-th peak of the femoral artery pulse wave It is obtained by subtracting the time point (time) of. In addition, the operation processing unit 220 is the ratio of the PWTT (cr-PWTT) between the carotid and radial arteries reflecting the stiffness of the central artery, and the PWTT (cf-PWTT) between the carotid and femoral arteries reflecting the stiffness of the peripheral arteries, PWTT ratio (PWTT ratio) is detected and the ratio is used as an indicator of cardiovascular and cerebrovascular disease risk analysis. In order to provide the measured signal and the ratio (PWTT ratio) as a graph and an index value, the state is indicated by outputting it to a display connected to the analysis unit 200.

9 is an example of a result of measuring a femoral artery with a blood flow change measurement sensor of the present invention and a sensor using a commercially available strap.

Even with the blood flow change measurement sensor of the present invention, a result similar to that of a sensor using a conventional strap was obtained.

The following table is a blood flow change measurement sensor of the present invention and a sensor using a commercially available strap (Biopac), which shows the blood flow conversion signal (pulse wave) in the carotid artery, the radial artery, and the femoral artery. This is an example of the result of measuring the error mean and standard deviation of the data.

It can be seen that the peak difference between the blood flow change measurement sensor of the present invention and the sensor using a commercially available strap is 12.96 msec at the minimum and 44.10 msec at the maximum, and can be used to detect a blood flow conversion signal (pulse wave).

The present invention is made of silicone or other member that can be attached to the skin, and the suction cup 100 blocks the inflow and outflow of air to the outside when it is adsorbed in the form of a cup, and the blood flow in the suction cup 100 An air pressure change measurement sensor 170 that detects changes in atmospheric pressure within the skin and structures, a control unit 75 and a transmission/reception unit 77 that receive signals from the air pressure change measurement sensor 170 and transmit the signals to the external analysis unit 200 It is made including.

In addition, the analysis unit 200 calculates a PWTT ratio for analyzing the risk of cardiovascular and cerebrovascular diseases by processing the received pulse wave signal, and outputs the measurement result through the display unit.

The suction cup 100 is connected to the rim 130 in contact with the skin, a spherical or cylindrical body above the rim 130, an air pressure change measurement sensor 170 mounted on the inner top, and an air pressure change measurement sensor 170 from the outside. It includes a through hole 120 through which the electric wire 150 passes, and a packing unit 110 that fixes the air pressure change measurement sensor 170 and prevents air from flowing into the through hole 120.

After attaching the adsorption cup 100 to the skin, the adsorption cup 100 is contracted or air is removed from the outside and adsorbed to fix it. When fixed in this way, it is fixed by pressure without any additional fixing device.

The barometric pressure change measurement sensor uses a sensor with sensitivity that can detect changes in atmospheric pressure due to changes in blood flow (approx. Resolution: 0.02 mbar), and is placed on the inner top of the adsorption cup, and the pressure between the skin and the adsorption cup due to blood flow changes. Detect changes. In detail, blood flows according to the cardiac output. When the suction cup is attached to the area under the measurement, the change in blood flow transmitted by the blood flow to the blood vessel under the skin is transmitted to the skin, and the resulting vibration is transmitted to the air between the suction cup and the skin. And the vibration is detected by the barometric pressure change measurement sensor.

The line that comes out for data transmission must pass through the air pressure change measurement sensor and the attachment part of the suction cup to the outside, and must be sealed with a packing part 110 that prevents air from passing when adsorbed to the part.

After that, the signal received from the sensor in the analysis unit 200 is sampled at 20 to 50 Hz to obtain a signal. At this time, the signal received by the measuring device from the barometric pressure change measurement sensor is a waveform as shown in FIG. 9.

10 is a flowchart illustrating a process of transmitting a blood flow change signal from the signal measurement unit 70 of FIG. 7 to the analysis unit 200.

In the initializing step, as the operation processing unit 220 transmits a blood flow change measurement start signal to the signal measurement unit 70, the control unit 75 of the signal measurement unit 70 includes three blood flow change measurement sensors 100, that is, The first blood flow change measurement sensor (blood flow change measurement sensor installed in the carotid artery), the second blood flow change measurement sensor (blood flow change measurement sensor installed in the radial artery), the third blood flow change measurement sensor (blood flow change measurement installed in the femoral artery) The sensor) is initialized by applying power (S110).

In the first blood flow change signal receiving step, the first blood flow change measurement sensor, that is, the pressure change measurement sensor 170 of the blood flow change measurement sensor mounted on the carotid artery, is an air pressure change signal in the suction cup 105 mounted on the carotid artery. , A blood flow change signal (this may be referred to as a pulse wave signal) is detected as a first blood flow change signal (ie, a blood flow change signal of the carotid artery), and the control unit 75 of the signal measurement unit 70 is the first blood flow change signal Put a first identifier indicating the first blood flow change signal before and after (the blood flow change signal of the carotid artery), and transmit it through the transmission/reception unit 77 of the signal measurement unit 70, and the calculation processing unit of the analysis unit 200 200 receives this (S120).

In the step of detecting the maximum value of the first blood flow change, the operation processing unit 200 determines whether the current first blood flow change received in the first blood flow change signal receiving step is greater than the previously stored first blood flow change maximum value. If it is large, the first blood flow change maximum value is updated with the current first blood flow change signal (S135).

In the second blood flow change signal reception step, the second blood flow change measurement sensor, that is, the barometric pressure change measurement sensor 170 of the blood flow change measurement sensor mounted on the radial artery, is the barometric pressure change in the absorption cup 105 mounted on the radial artery. A signal, a blood flow change signal (which may also be referred to as a pulse wave signal) is detected as a second blood flow change signal (ie, a blood flow change signal of the radial artery), and the control unit 75 of the signal measurement unit 70 controls the second Before and after the blood flow change signal (blood flow change signal of the radial artery), a second identifier indicating the second blood flow change signal is put, and this is transmitted through the transmission/reception unit 77 of the signal measurement unit 70, and the analysis unit 200 ) Of the operation processing unit 200 receives it (S120).

In the step of detecting the maximum value of the second blood flow change, the operation processing unit 200 determines whether the current second blood flow change received in the second blood flow change signal reception step is greater than the previously stored second blood flow change maximum value. If it is large, the second blood flow change maximum value is updated with the current second blood flow change signal (S170).

In the third blood flow change signal reception step, the third blood flow change measurement sensor, that is, the barometric pressure change measurement sensor 170 of the blood flow change measurement sensor mounted on the femoral artery, is the barometric pressure change in the absorption cup 105 mounted on the femoral artery. A signal, a blood flow change signal (which may also be referred to as a pulse wave signal) is detected as a third blood flow change signal (ie, a blood flow change signal of the femoral artery), and the control unit 75 of the signal measurement unit 70 controls the third Before and after the blood flow change signal (blood flow change signal of the femoral artery), a third identifier indicating the third blood flow change signal is put, and this is transmitted through the transmission/reception unit 77 of the signal measurement unit 70, and the analysis unit 200 ), the operation processing unit 200 receives it (S180).

In the step of detecting the maximum value of the third blood flow change, the operation processing unit 200 determines whether the current third blood flow change received in the third blood flow change signal reception step is greater than the previously stored third blood flow change maximum value. If it is large (S185), the maximum value of the third blood flow change is updated with the current second blood flow change signal (S187).

11 is a flowchart illustrating a process of detecting a PWTT by detecting a peak in each blood flow change signal in the operation processing unit 220 of the analysis unit 200 of FIG. 7.

11 is a process of detecting a peak, that is, the R point of a pulse wave in the first blood flow change signal, the second blood flow change signal, and the third blood flow change signal, and calculating the average time interval between peaks (RR average time interval) at each time point. to be.

The data of the blood flow change signal during the window time interval is differentiated. By performing differentiation, the slope of each signal can be known. The window time interval is a preset value, a value set at the time of factory shipment or at the beginning of use, and may be, for example, 15 seconds or 30 seconds or 1 minute or 5 minutes.

In the step of detecting an inflection point, compare whether the previous differential value (i.e., previous slope) is greater than '0' and the current differential value (now slope) is less than or equal to '0' (that is, whether it is an inflection point). Comparison) (S210), waits until a value of the previous derivative (that is, the previous slope) is greater than '0' and the current derivative (now slope) is less than or equal to '0'. In other words, it waits for a blood flow change signal that becomes an inflection point. In other words, if the previous differential value (that is, the previous slope) is greater than '0', and the current differential value (now slope) is not less than or equal to '0', it returns to the inflection point detection step and detects again.

In the peak candidate detection step, if the previous differential value (i.e., the previous slope) detected in the inflection point detection step is greater than '0' and the current differential value (now slope) has a value less than or equal to '0', It is determined whether the current blood flow change signal is greater than the peak detection threshold (S220), and if the current blood flow change signal is greater than the peak detection threshold, it is set as a peak candidate, and waits until a value greater than the peak detection threshold is displayed. That is, if the current blood flow change signal is not greater than the peak detection threshold, the process returns to the inflection point detection step and detects again. Here, the peak detection threshold is a value obtained by multiplying the maximum value of blood flow change obtained through the flowchart of FIG. 10 by 0.8.

This is the time interval comparison step between the peak candidate and the successive peaks, and the time interval between the peak candidate and the subsequent previous peaks, obtained in the peak candidate detection step, i.e., the value obtained by subtracting the time points of the peaks before and after the peak candidates is the minimum. It waits until a value greater than the time interval threshold is displayed (S230). Here, if the time interval between the peak candidate and the previous peak successively is less than the minimum time interval threshold, it returns to the inflection point detection step. Here, the minimum time interval threshold is a minimum consecutive peak interval (ie, minimum RR interval), a value set at the time of factory shipment or at the beginning of use, and may be 0.3 seconds.

In the peak detection step, in the step of comparing the time interval between the peak candidate and the subsequent previous peak, if the time interval between the peak candidate and the subsequent previous peak is greater than the minimum time interval threshold, the current peak candidate, that is, the current blood flow change signal, is displayed. The peak is stored in the memory unit 250 (S240).

As a step of confirming the number of peaks, after the peak detection step, it is determined whether there are three or more consecutive peaks stored in the memory unit 250, and if three consecutive peaks are not more than three, it returns to the inflection point detection step, and there are three or more consecutive peaks. Wait until it becomes (S250).

This is the detection step of the average time interval between successive peaks. If there are three or more consecutive peaks in the step of confirming the number of peaks, the average of the time intervals of the three consecutive peaks is calculated, stored as a PWTT signal, and output.

In the present invention, PWTT (cr-PWTT) between the carotid and radial arteries is detected by subtracting the average time interval between peaks of the carotid blood flow conversion signal from the average time interval between peaks of the radial artery blood flow conversion signal.

Further, in the present invention, PWTT (cr-PWTT) between the carotid artery and the femoral artery is detected by subtracting the average time interval between peaks of the carotid artery blood flow conversion signal from the average time interval between peaks of the femoral artery blood flow conversion signal.

As described above, although the present invention has been described by the limited embodiments and drawings, the present invention is not limited to the above embodiments, which is various modifications and variations from these descriptions to those of ordinary skill in the field to which the present invention belongs. Transformation is possible. Accordingly, the spirit of the present invention should be grasped only by the claims set forth below, and all equivalent or equivalent modifications thereof will be said to belong to the scope of the present invention.

Claims (12)

Adsorption cup made to be attached to the skin having a through hole at the top;
An air pressure change measuring sensor mounted inside the suction cup and detecting a change in air pressure inside the suction cup as a blood flow conversion signal;
When the wire connected to the barometric pressure change measurement sensor is inserted into the through hole, a packing unit that prevents air from leaking from the through hole;
And,
In order to mount the blood flow change measurement sensor in the area where the carotid artery, radial artery and femoral artery are located, the blood flow change measurement sensor has three, and detects the carotid artery blood flow conversion signal, the radial artery blood flow conversion signal, and the femoral artery blood flow conversion signal. And
The control unit includes an identifier representing one of the carotid artery blood flow conversion signal, the radial artery blood flow conversion signal, or the femoral artery blood flow conversion signal, and transmits it to the analysis unit through the transmission/reception unit by putting an identifier in front and behind the blood flow conversion signal. Change measuring device. A blood flow change measurement sensor for detecting a change in pressure of air inside the suction cup as a blood flow conversion signal by using an air pressure change measurement sensor located inside the suction cup;
A signal preprocessor for amplifying the blood flow conversion signal detected by the blood flow change measurement sensor, removing noise, and converting it into a digital signal;
A control unit for transmitting the blood flow conversion signal input from the signal preprocessor to the analysis unit through the transmission/reception unit;
Including
In order to mount the blood flow change measurement sensor in the area where the carotid artery, radial artery and femoral artery are located, the blood flow change measurement sensor has three, and detects the carotid artery blood flow conversion signal, the radial artery blood flow conversion signal, and the femoral artery blood flow conversion signal. And
The control unit includes an identifier representing one of the carotid artery blood flow conversion signal, the radial artery blood flow conversion signal, or the femoral artery blood flow conversion signal, and transmits it to the analysis unit through the transmission/reception unit by putting an identifier in front and behind the blood flow conversion signal. Change measuring device. delete delete The method according to any one of claims 1 or 2,
The analysis unit receives the carotid artery blood flow conversion signal, the radial artery blood flow conversion signal, and the femoral artery blood flow conversion signal, and calculates the ratio of the PWTT (Pluse Wave Transit Time) between the carotid and radial arteries, and the PWTT between the carotid and femoral arteries. A blood flow change measurement device. delete Using the pressure change measurement sensor located inside the suction cup, the blood flow change measurement sensors that detect the pressure change of the air inside the suction cup as a blood flow conversion signal are located at the location of the carotid artery, the location of the radial artery, and the location of the femoral artery. A blood flow change measurement step in which the blood flow change measurement sensors detect a carotid artery blood flow conversion signal, a radial artery blood flow conversion signal, and a femoral artery blood flow conversion signal;
Each blood flow conversion signal, including the carotid artery blood flow conversion signal, the radial artery blood flow conversion signal, and the femoral artery blood flow conversion signal detected in the blood flow change measurement step, is received as a pulse wave signal, and the analysis unit receives the cycle at each blood flow conversion signal. An analysis step of detecting each peak, and detecting a time interval between the peak and the subsequent peak as PWTT of each blood flow conversion signal;
It includes, and the analysis step,
The analysis unit differentiates each blood flow conversion signal, compares whether the previous differential value (previous slope) is greater than '0' and the current differential value (current slope) is less than or equal to '0', and the previous differential value is A step of detecting an inflection point, waiting for a value greater than '0' and a current differential value less than or equal to '0';
The analysis unit determines whether the current blood flow change signal is greater than the peak detection threshold if the previous differential value detected in the inflection point detection step is greater than '0' and the current differential value has a value less than or equal to '0'. And, if the current blood flow change signal is greater than the peak detection threshold, the peak candidate detection step;
The analysis unit compares whether the time interval between the peak candidate and all subsequent peaks obtained in the peak candidate detection step is greater than a preset minimum time interval threshold, and the time interval between the peak candidate and the subsequent previous peaks is the minimum time interval threshold. A peak detection step of storing a current blood flow change signal, which is a current peak candidate, as a current peak in the memory unit;
After the peak detection step, the analysis unit determines whether there are three or more consecutive peaks stored in the memory unit, and if there are three or more consecutive peaks, the average of the time intervals of the three consecutive peaks is calculated as PWTT, between consecutive peaks. Detecting an average time interval;
It characterized in that it comprises a, driving method of the blood flow change measuring device. The method of claim 7, wherein the analysis step,
The analysis unit detects the PWTT (Pluse Wave Transit Time) between the carotid and radial arteries and the ratio of the PWTT between the carotid and femoral arteries using the PWTT of each blood flow conversion signal, and outputs them as an index for analyzing cardiovascular and cerebrovascular disease risk. A method of driving a blood flow change measuring device. delete The method of claim 7,
In the peak candidate detection step, the peak detection threshold is a value obtained by multiplying the maximum value of the previously detected blood flow change signal by 0.8. The method of claim 10,
A method of driving a blood flow change measuring apparatus, characterized in that the minimum time interval threshold is 0.3 seconds. delete

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